refactor: new way to get interface change even for linux

listener/tun/ipstack/commons/auto_linux.go

@@ -0,0 +1,90 @@
+package commons
+
+import (
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/iface"
+	"github.com/Dreamacro/clash/log"
+	"github.com/vishvananda/netlink"
+	"go.uber.org/atomic"
+	"time"
+)
+
+var (
+	monitorStarted = atomic.NewBool(false)
+	monitorStop    = make(chan struct{}, 2)
+)
+
+func StartDefaultInterfaceChangeMonitor() {
+	go func() {
+		if monitorStarted.Load() {
+			return
+		}
+		monitorStarted.Store(true)
+
+		done := make(chan struct{})
+		ch := make(chan netlink.RouteUpdate, 2)
+		err := netlink.RouteSubscribe(ch, done)
+		if err != nil {
+			log.Warnln("[TUN] auto detect interface fail: %s", err)
+			return
+		}
+		log.Debugln("[TUN] start auto detect interface monitor")
+		defer func() {
+			close(done)
+			monitorStarted.Store(false)
+			log.Debugln("[TUN] stop auto detect interface monitor")
+		}()
+
+		select {
+		case <-monitorStop:
+		default:
+		}
+
+		for {
+			select {
+			case <-monitorStop:
+				return
+			case <-ch:
+			}
+
+			interfaceName, err := GetAutoDetectInterface()
+			if err != nil {
+				t := time.NewTicker(2 * time.Second)
+				for {
+					select {
+					case ch <- <-ch:
+						break
+					case <-t.C:
+						interfaceName, err = GetAutoDetectInterface()
+						if err != nil {
+							continue
+						}
+					}
+					break
+				}
+				t.Stop()
+			}
+
+			if err != nil {
+				log.Debugln("[TUN] detect interface: %s", err)
+				continue
+			}
+
+			old := dialer.DefaultInterface.Load()
+			if interfaceName == old {
+				continue
+			}
+
+			dialer.DefaultInterface.Store(interfaceName)
+			iface.FlushCache()
+
+			log.Warnln("[TUN] default interface changed by monitor, %s => %s", old, interfaceName)
+		}
+	}()
+}
+
+func StopDefaultInterfaceChangeMonitor() {
+	if monitorStarted.Load() {
+		monitorStop <- struct{}{}
+	}
+}

listener/tun/ipstack/commons/auto_others.go

@@ -0,0 +1,67 @@
+//go:build !linux
+
+package commons
+
+import (
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/iface"
+	"github.com/Dreamacro/clash/log"
+	"go.uber.org/atomic"
+	"time"
+)
+
+var (
+	monitorDuration = 3 * time.Second
+	monitorStarted  = atomic.NewBool(false)
+	monitorStop     = make(chan struct{}, 2)
+)
+
+func StartDefaultInterfaceChangeMonitor() {
+	go func() {
+		if monitorStarted.Load() {
+			return
+		}
+		monitorStarted.Store(true)
+		t := time.NewTicker(monitorDuration)
+		log.Debugln("[TUN] start auto detect interface monitor")
+		defer func() {
+			monitorStarted.Store(false)
+			t.Stop()
+			log.Debugln("[TUN] stop auto detect interface monitor")
+		}()
+
+		select {
+		case <-monitorStop:
+		default:
+		}
+
+		for {
+			select {
+			case <-t.C:
+				interfaceName, err := GetAutoDetectInterface()
+				if err != nil {
+					log.Warnln("[TUN] default interface monitor err: %v", err)
+					continue
+				}
+
+				old := dialer.DefaultInterface.Load()
+				if interfaceName == old {
+					continue
+				}
+
+				dialer.DefaultInterface.Store(interfaceName)
+				iface.FlushCache()
+
+				log.Warnln("[TUN] default interface changed by monitor, %s => %s", old, interfaceName)
+			case <-monitorStop:
+				break
+			}
+		}
+	}()
+}
+
+func StopDefaultInterfaceChangeMonitor() {
+	if monitorStarted.Load() {
+		monitorStop <- struct{}{}
+	}
+}

listener/tun/ipstack/commons/router.go

@@ -2,21 +2,13 @@ package commons
 
 import (
 	"fmt"
-	"github.com/Dreamacro/clash/component/dialer"
-	"github.com/Dreamacro/clash/component/iface"
 	"github.com/Dreamacro/clash/log"
 	"net"
-	"sync"
 	"time"
 )
 
 var (
 	defaultRoutes = []string{"1.0.0.0/8", "2.0.0.0/7", "4.0.0.0/6", "8.0.0.0/5", "16.0.0.0/4", "32.0.0.0/3", "64.0.0.0/2", "128.0.0.0/1"}
-
-	monitorDuration = 3 * time.Second
-	monitorStarted  = false
-	monitorStop     = make(chan struct{}, 2)
-	monitorMux      sync.Mutex
 )
 
 func ipv4MaskString(bits int) string {
@@ -28,59 +20,6 @@ func ipv4MaskString(bits int) string {
 	return fmt.Sprintf("%d.%d.%d.%d", m[0], m[1], m[2], m[3])
 }
 
-func StartDefaultInterfaceChangeMonitor() {
-	go func() {
-		monitorMux.Lock()
-		if monitorStarted {
-			monitorMux.Unlock()
-			return
-		}
-		monitorStarted = true
-		monitorMux.Unlock()
-
-		select {
-		case <-monitorStop:
-		default:
-		}
-
-		t := time.NewTicker(monitorDuration)
-		defer t.Stop()
-
-		for {
-			select {
-			case <-t.C:
-				interfaceName, err := GetAutoDetectInterface()
-				if err != nil {
-					log.Warnln("[TUN] default interface monitor err: %v", err)
-					continue
-				}
-
-				old := dialer.DefaultInterface.Load()
-				if interfaceName == old {
-					continue
-				}
-
-				dialer.DefaultInterface.Store(interfaceName)
-				iface.FlushCache()
-
-				log.Warnln("[TUN] default interface changed by monitor, %s => %s", old, interfaceName)
-			case <-monitorStop:
-				break
-			}
-		}
-	}()
-}
-
-func StopDefaultInterfaceChangeMonitor() {
-	monitorMux.Lock()
-	defer monitorMux.Unlock()
-
-	if monitorStarted {
-		monitorStop <- struct{}{}
-		monitorStarted = false
-	}
-}
-
 func WaitForTunClose(deviceName string) {
 	t := time.NewTicker(600 * time.Millisecond)
 	defer t.Stop()

listener/tun/ipstack/commons/router_linux.go

@@ -10,7 +10,11 @@ import (
 )
 
 func GetAutoDetectInterface() (string, error) {
-	return cmd.ExecCmd("bash -c ip route show | grep 'default via' | awk -F ' ' 'NR==1{print $5}' | xargs echo -n")
+	execCmd, err := cmd.ExecCmd("bash -c ip route show | grep 'default via' | awk -F ' ' 'NR==1{print $5}' | xargs echo -n")
+	if execCmd == "" {
+		return "", fmt.Errorf("interface not found")
+	}
+	return execCmd, err
 }
 
 func ConfigInterfaceAddress(dev device.Device, addr netip.Prefix, forceMTU int, autoRoute bool) error {